DELRAY BEACH, FL - OCTOBER 21: Republican presidential candidate, former Massachusetts Gov. Mitt Romney (C) is flanked by U.S. Secret Service agents and staff as he walks to the beach prior to the start of a touch football game on the beach with members of the Romney campaign staff versus some members of the traveling press corps on October 21, 2012 in Delray Beach, Florida. With one day to go before the third and final presidential debate with U.S. President Barack Obama, Mitt Romney is spending the day doing debate prep. (Photo by Justin Sullivan/Getty Images) less

DELRAY BEACH, FL - OCTOBER 21: Republican presidential candidate, former Massachusetts Gov. Mitt Romney (C) is flanked by U.S. Secret Service agents and staff as he walks to the beach prior to the start of a ... more

RENO, NV - OCTOBER 24: U.S. Secret Service agents wait for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to walk off of his campaign plane on October 24, 2012 in Reno, Nevada. Mitt Romney is campaigning in Nevada, Iowa and Ohio. (Photo by Justin Sullivan/Getty Images) less

RENO, NV - OCTOBER 24: U.S. Secret Service agents wait for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to walk off of his campaign plane on October 24, 2012 in Reno, Nevada. Mitt ... more

RENO, NV - OCTOBER 24: A U.S. Secret Service agent is silhouetted by stage lights as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at the Reno Event Center on October 24, 2012 in Reno, Nevada. Mitt Romney is campaigning in Nevada, Iowa and Ohio. (Photo by Justin Sullivan/Getty Images) less

RENO, NV - OCTOBER 24: A U.S. Secret Service agent is silhouetted by stage lights as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at the Reno Event ... more

Photo: Justin Sullivan, Getty Images

RENO, NV - OCTOBER 24: A U.S. Secret Service agent is silhouetted... Photo-3711522.52152 - Houston Chronicle

Image 4 of 44

NORTH CANTON, OH - OCTOBER 26: A U.S. Secret Service agent looks on as Republican presidential candidate, former Massachusetts Gov. Mitt Romney and his running mate U.S. Rep. Paul Ryan (R-WI) speak during a campaign rally at Hoover High School on October 26, 2012 in Akron, Ohio. With less than two weeks before election day, Mitt Romney is campaigning in Iowa and Ohio. (Photo by Justin Sullivan/Getty Images) less

NORTH CANTON, OH - OCTOBER 26: A U.S. Secret Service agent looks on as Republican presidential candidate, former Massachusetts Gov. Mitt Romney and his running mate U.S. Rep. Paul Ryan (R-WI) speak during a ... more

Photo: Justin Sullivan, Getty Images

NORTH CANTON, OH - OCTOBER 26: A U.S. Secret Service agent looks... Photo-3711523.52152 - Houston Chronicle

Image 5 of 44

Taboola Gallery Frame Item-85307.52152 - Houston Chronicle

Image 6 of 44

DAVENPORT, IA - OCTOBER 29: U.S. Secret Service agents surround Republican presidential candidate, former Massachusetts Gov. Mitt Romney (3rd L) and his personal aide Garrett Jackson (R) as they wait backstage before a campaign rally at Seven Cities Sod on October 29, 2012 in Davenport, Iowa. Romney has canceled other campaign events on October 29 and 30 due to Hurrcane Sandy. (Photo by Justin Sullivan/Getty Images) less

MOLINE, IL - OCTOBER 29: A U.S. Secret Service agent stands on the tarmac as the campaign plane of Republican presidential candidate, former Massachusetts Gov. Mitt Romney lands at Quad Cities International Airport on October 29, 2012 in Moline, Illinois. Romney has canceled other campaign events on October 29 and 30 due to Hurricane Sandy. (Photo by Justin Sullivan/Getty Images) less

MOLINE, IL - OCTOBER 29: A U.S. Secret Service agent stands on the tarmac as the campaign plane of Republican presidential candidate, former Massachusetts Gov. Mitt Romney lands at Quad Cities International ... more

DOSWELL, VA - NOVEMBER 01: U.S. Secret Service agents surround Republican presidential candidate, former Massachusetts Gov. Mitt Romney as he preapres to board his campaign bus at the conclusion of a campaign event at Meadow Event Park on November 1, 2012 in Doswell, Virginia. With less than one week to go until election day, Romney is campaigning in Virginia. (Photo by Justin Sullivan/Getty Images) less

DOSWELL, VA - NOVEMBER 01: U.S. Secret Service agents surround Republican presidential candidate, former Massachusetts Gov. Mitt Romney as he preapres to board his campaign bus at the conclusion of a campaign ... more

NORFOLK, VA - NOVEMBER 02: A U.S. Secret Service agent stands guard in front of the hotel room of Republican presidential candidate, former Massachusetts Gov. Mitt Romney on November 2, 2012 in Norfolk, Virginia. With less than one week to go before election day, Mitt Romney is campaigning in Wisconsin and Ohio. (Photo by Justin Sullivan/Getty Images) less

NORFOLK, VA - NOVEMBER 02: A U.S. Secret Service agent stands guard in front of the hotel room of Republican presidential candidate, former Massachusetts Gov. Mitt Romney on November 2, 2012 in Norfolk, ... more

DUBUQUE, IA - NOVEMBER 03: U.S. Secret Service agents monitor the crowd as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Dubuque Jet Center on November 3, 2012 in Dubuque, Iowa. With less than a week before election day, Romney is campaigning in battleground states across the country. (Photo by Justin Sullivan/Getty Images) less

DUBUQUE, IA - NOVEMBER 03: U.S. Secret Service agents monitor the crowd as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Dubuque Jet Center on ... more

DUBUQUE, IA - NOVEMBER 03: U.S. Secret Service agents monitor the crowd as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Dubuque Jet Center on November 3, 2012 in Dubuque, Iowa. With less than a week before election day, Romney is campaigning in battleground states across the country. (Photo by Justin Sullivan/Getty Images) less

DUBUQUE, IA - NOVEMBER 03: U.S. Secret Service agents monitor the crowd as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at Dubuque Jet Center on ... more

ENGLEWOOD, CO - NOVEMBER 03: U.S. Secret Service agents keep watch as a video screen displays Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaking during a campaign rally at Comfort Dental Amphitheater on November 3, 2012 in Englewood, Colorado. With less than a week before election day, Mitt Romney is campaigning across the country. (Photo by Justin Sullivan/Getty Images) less

ENGLEWOOD, CO - NOVEMBER 03: U.S. Secret Service agents keep watch as a video screen displays Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaking during a campaign rally at ... more

ENGLEWOOD, CO - NOVEMBER 03: A U.S. Secret Service agent watches as an aide pulls the curtain aside for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to enter a campaign rally at Comfort Dental Amphitheater on November 3, 2012 in Englewood, Colorado. With less than a week before election day, Mitt Romney is campaigning across the country. (Photo by Justin Sullivan/Getty Images) less

ENGLEWOOD, CO - NOVEMBER 03: A U.S. Secret Service agent watches as an aide pulls the curtain aside for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to enter a campaign rally at ... more

SANFORD, FL - NOVEMBER 05: Republican presidential candidate, former Massachusetts Gov. Mitt Romney walks with U.S. Secret Service agents as he leaves a campaign rally at Avion Jet Center on November 5, 2012 in Sanford, Florida. With one day to go until election day, Romney is making one final push throughout swing states. (Photo by Justin Sullivan/Getty Images) less

SANFORD, FL - NOVEMBER 05: Republican presidential candidate, former Massachusetts Gov. Mitt Romney walks with U.S. Secret Service agents as he leaves a campaign rally at Avion Jet Center on November 5, 2012 ... more

An US Secret Service agent talks into his mouth piece as US Republican presidential candidate Mitt Romney (2nd L) shakes hands with supporters after speaking at a victory rally in Richmond, Virginia, October 12, 2012. AFP PHOTO/Jim WATSONJIM WATSON/AFP/GettyImages less

An US Secret Service agent talks into his mouth piece as US Republican presidential candidate Mitt Romney (2nd L) shakes hands with supporters after speaking at a victory rally in Richmond, Virginia, October ... more

Photo: JIM WATSON, AFP/Getty Images

An US Secret Service agent talks into his mouth piece as US... Photo-3711533.52152 - Houston Chronicle

Image 18 of 44

A US Secret Service agent keeps watch behind the stage as US Republican presidential candidate Mitt Romney (rear) delivers remarks at a victory rally Lebanon, Ohio, October 13, 2012. As the election draws nearer, the press pool and staff member work around the clock in plain sight, as well as behind the scenes, as US Republican Presidential candidate Mitt Romeny travels across the country to deliver his message. AFP PHOTO/Jim WATSONJIM WATSON/AFP/GettyImages less

A US Secret Service agent keeps watch behind the stage as US Republican presidential candidate Mitt Romney (rear) delivers remarks at a victory rally Lebanon, Ohio, October 13, 2012. As the election draws ... more

Photo: JIM WATSON, AFP/Getty Images

A US Secret Service agent keeps watch behind the stage as US... Photo-3711534.52152 - Houston Chronicle

Image 19 of 44

An US Secret Service agent stands lookout from atop a building as US Republican presidential candidate Mitt Romney (C) delivers remarks at a victory rally Lebanon, Ohio, October 13, 2012. As the election draws nearer, the press pool and staff member work around the clock in plain sight, as well as behind the scenes, as US Republican Presidential candidate Mitt Romeny travels across the country to deliver his message. AFP PHOTO/Jim WATSONJIM WATSON/AFP/GettyImages less

An US Secret Service agent stands lookout from atop a building as US Republican presidential candidate Mitt Romney (C) delivers remarks at a victory rally Lebanon, Ohio, October 13, 2012. As the election draws ... more

Photo: JIM WATSON, AFP/Getty Images

An US Secret Service agent stands lookout from atop a building as... Photo-3711535.52152 - Houston Chronicle

Image 20 of 44

Taboola Gallery Frame Item-85307.52152 - Houston Chronicle

Image 21 of 44

US Secret Service agent shadows Mitt Romney with his armored SUV as he works a ropeline of supporters at an airplane hangar in Cedar Rapids, Iowa #aponthetrail (AP Photo/Charles Dharapak)

US Secret Service agent shadows Mitt Romney with his armored SUV as he works a ropeline of supporters at an airplane hangar in Cedar Rapids, Iowa #aponthetrail (AP Photo/Charles Dharapak)

A secret service agent stands guard outside in front of an overflow crowd before Republican presidential candidate, former Massachusetts Gov. Mitt Romney exits a campaign event at George Mason University, ... more

Photo: David Goldman, Associated Press

A secret service agent stands guard outside in front of an overflow... Photo-3711539.52152 - Houston Chronicle

Image 25 of 44

Taboola Gallery Frame Item-85307.52152 - Houston Chronicle

Image 26 of 44

Secret service agents stand next to air stairs as they wait for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to arrive on his plane next to a crowd of supporters, at right, for a campaign event at Dubuque Regional Airport, Saturday, Nov. 3, 2012, in Dubuque, Iowa. (AP Photo/David Goldman) less

Secret service agents stand next to air stairs as they wait for Republican presidential candidate, former Massachusetts Gov. Mitt Romney to arrive on his plane next to a crowd of supporters, at right, for a ... more

Photo: David Goldman, Associated Press

Secret service agents stand next to air stairs as they wait for... Photo-3711540.52152 - Houston Chronicle

Image 27 of 44

Republican presidential candidate, former Massachusetts Gov. Mitt Romney smiles as he speaks to a U.S. Secret Service agent before boarding his plane in Bedford Mass., for Cleveland, Ohio, Tuesday, Nov. 6, 2012. (AP Photo/Charles Dharapak) less

Republican presidential candidate, former Massachusetts Gov. Mitt Romney smiles as he speaks to a U.S. Secret Service agent before boarding his plane in Bedford Mass., for Cleveland, Ohio, Tuesday, Nov. 6, ... more

A secret service agent looks toward the stage before Republican presidential candidate, former Massachusetts Gov. Mitt Romney, appears to speak at a campaign event at the International Exposition Center, Sunday, Nov. 4, 2012, in Cleveland. (AP Photo/David Goldman) less

A secret service agent looks toward the stage before Republican presidential candidate, former Massachusetts Gov. Mitt Romney, appears to speak at a campaign event at the International Exposition Center, ... more

Secret Service agents stand watch as Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks during a campaign rally at the Shelby County Fairgrounds on Wednesday, Oct. 10, 2012 in ... more

U.S. Secret Service agents watch as Republican presidential candidate, former Massachusetts Gov. Mitt Romney walks in a drizzle to board his campaign plane in Vandalia, Ohio, Tuesday, Oct. 30, 2012, as he travels to Tampa, Fla. for a campaign stop. (AP Photo/Charles Dharapak) less

U.S. Secret Service agents watch as Republican presidential candidate, former Massachusetts Gov. Mitt Romney walks in a drizzle to board his campaign plane in Vandalia, Ohio, Tuesday, Oct. 30, 2012, as he ... more

A U.S. Secret Service agent uses binoculars to look out from the vacation home of Republican presidential candidate, former Massachusetts Gov. Mitt Romney on Lake Winnipesaukee in Wolfeboro, N.H., Thursday, July 5, 2012. (AP Photo/Charles Dharapak) less

A U.S. Secret Service agent uses binoculars to look out from the vacation home of Republican presidential candidate, former Massachusetts Gov. Mitt Romney on Lake Winnipesaukee in Wolfeboro, N.H., Thursday, ... more

Photo: Charles Dharapak, Associated Press

A U.S. Secret Service agent uses binoculars to look out from the... Photo-3711546.52152 - Houston Chronicle

Image 34 of 44

Shadows are cast against a rock wall as secret service agents stand guard behind the stage where Republican presidential candidate, former Massachusetts Gov. Mitt Romney, speaks at a campaign event at the Red Rocks Amphitheatre Tuesday, Oct. 23, 2012, in Golden, Colo. (AP Photo/David Goldman) less

Shadows are cast against a rock wall as secret service agents stand guard behind the stage where Republican presidential candidate, former Massachusetts Gov. Mitt Romney, speaks at a campaign event at the Red ... more

Photo: David Goldman, Associated Press

Shadows are cast against a rock wall as secret service agents stand... Photo-3711547.52152 - Houston Chronicle

Image 35 of 44

Taboola Gallery Frame Item-85307.52152 - Houston Chronicle

Image 36 of 44

A U.S. Secret Service agent, left, pulls the hand of an unidentified man, background center in white shirt, who would not let go of the hand of Republican presidential candidate and former Massachusetts Gov. Mitt Romney, foreground, as he shakes hands while campaigning at Colorado Springs Municipal Airport in Colorado Springs, Col., Saturday, Nov. 3, 2012. The man was not later detained. (AP Photo/Charles Dharapak) less

A U.S. Secret Service agent, left, pulls the hand of an unidentified man, background center in white shirt, who would not let go of the hand of Republican presidential candidate and former Massachusetts Gov. ... more

Photo: Charles Dharapak, Associated Press

A U.S. Secret Service agent, left, pulls the hand of an... Photo-3711548.52152 - Houston Chronicle

Image 37 of 44

A U.S. Secret Service agent stands watch as the crowd cheers while Republican presidential candidate and former Massachusetts Gov. Mitt Romney and his vice presidential running mate, Rep. Paul Ryan, R-Wis., campaign at the baseball field of North Canton Hoover High School in North Canton, Ohio, Friday, Oct. 26, 2012. (AP Photo/Charles Dharapak) less

A U.S. Secret Service agent stands watch as the crowd cheers while Republican presidential candidate and former Massachusetts Gov. Mitt Romney and his vice presidential running mate, Rep. Paul Ryan, R-Wis., ... more

Photo: Charles Dharapak, Associated Press

A U.S. Secret Service agent stands watch as the crowd cheers while... Photo-3711549.52152 - Houston Chronicle

Image 38 of 44

Republican presidential candidate and former Massachusetts Gov. Mitt Romney is accompanied by a U.S. Secret Service agent as he walks at a loading dock at his hotel in Norfolk, Va., Thursday, Nov. 1, 2012, as he finishes a day of campaigning. (AP Photo/Charles Dharapak) less

Republican presidential candidate and former Massachusetts Gov. Mitt Romney is accompanied by a U.S. Secret Service agent as he walks at a loading dock at his hotel in Norfolk, Va., Thursday, Nov. 1, 2012, as ... more

Accompanied by U.S. Secret Service agents, Republican presidential candidate and former Massachusetts Gov. Mitt Romney begins to run towards an overflow crowd gathered outside of Celina Fieldhouse in Celina Ohio. He addressed the audience along with his vice presidential running mate, Rep. Paul Ryan. (AP Photo/Charles Dharapak) less

Accompanied by U.S. Secret Service agents, Republican presidential candidate and former Massachusetts Gov. Mitt Romney begins to run towards an overflow crowd gathered outside of Celina Fieldhouse in Celina ... more

Republican presidential candidate and former Massachusetts Gov. Mitt Romney, aide Garret Jackson, second left, and U.S. Secret Service agents get into an elevator as they arrive at their hotel for the evening in Mansfield, Ohio, Sunday, Oct. 28, 2012. (AP Photo/Charles Dharapak) less

Republican presidential candidate and former Massachusetts Gov. Mitt Romney, aide Garret Jackson, second left, and U.S. Secret Service agents get into an elevator as they arrive at their hotel for the evening ... more

A U.S. Secret Service agent, left, stands watch as Republican presidential candidate and former Massachusetts Gov. Mitt Romney and his vice presidential running mate Rep. Paul Ryan, R-Wis., greet supporters during a photo line backstage before the start of a campaign rally at Koehler Athletic Complex, University of Findlay, Sunday, Oct. 28, 2012, in Findlay, Ohio. (AP Photo/Charles Dharapak) less